Expansive underreamer



Get 9 1923.,

L. H. BALDWHN EXPANSIVE UNDERREAMER Filed Oct. 5, 1921 Patented @ch 9,1923..

"we n. any: a ax ill b li All hill u ll LOUI H. BALDVJIN, OF OKLAHOMA,OKLAHOMA.

EXPANSIVE UNDERREAIEER.

-Application filed October 5, 1921. Serial lilo. 505,506.

useful Improvements in Expansive Underreamers; and I do hereby declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to new and useful improvements in boring devicesand particularly to well boring devices.

One object of the invention is to provide a boring device of thischaracter which can be used below the lower end of the casing or tube,to underream the wall of the well, so as to permit the use of tubesections of the same diameter throughout the entire depth of the well.

Another object resides in the particular construction and arrangement ofthe underreaming blades and the means for projecting them into operativeposition.

Other objects and advantages will be apparent from the followingdescription when taken in connection with the accompanying drawing.

In the drawing:

Figure 1 is an elevation of the invention, the tubing being shown insection.

Figure 2 is a longitudinal sectional view through the device.

Figure 3 is a perspective view of the slidable rod. for spreading thecutting blades, the outer tube being broken away, to show the wedgemembers.

Referring particularly to the accompanyins: drawing, 10 represents thesection of tubing which is let down into the hole in the ground and intowhich the drill bit is passed to project from the lower end in cuttingrelation to the wall of the hole.

A cylindrical casing 11 is formed with the central longitudinal bore 12and the later- :illv communicating openings 13, which la-ttcr are in thetorm of longitudinal, slots. Disposed through each of the slots 13 is anapproximately triangular blade 14. pivotally supported on the pin 15,which extends transversely of the upper end of the slot. Screwed intothe lower end of the casing 11 is the stem of the bit 16, and screwedinto the upper end of the casing is a coupling 17 which carries theupwardly extending tube 18. In opposite sides of this tube 18, adjacentthe coupling 17, there are formed the longitudinal slots 19. Disposedfor sliding movement longitudinally within the tube 17 is a smaller tube20 the lower end of which is formed with a head 21 having longitudinallyextending pin 22, and openings 23 at the sides of the pin, the saidopenings communicatinp with the interiorot the tube. Disposed throughthe slots 19, and transversely through the smaller tube 20 are thewedges 24 and 25, the latter being inserted between the former to holdthe same in proper position within the tube, while the ends of thewedges are arranged to play lon- Q'itudinally in the slots 19 to limitthe slidins: movement of the tube 20. In the opposite sides of the bit16 are openings which communicate with the interior of the casing 11 andthe tube 20, to permit the flow of water to the bit.

Ordinarily, when boring a Well, as the boring proceeds. it is necessary,from time to time. to introduce additional tube sections to hold backthe wall against being washed away. Each time a new tube section isinserted or added a smaller tube is used, with the result that thediameter of the hole is gradually reduced. With the present device it ispermitted to use additional tube sections of the same diameter as thatfirst used. thus resulting in a hole of the same dian e er throughoutits entire depth.

When it is desired to extend the drill, as the boring progresses. theadditional section of tube is joined to the first section of the drillrod and additional casinosections se cured to the upper end of thecasing 10. The smaller tube 20 is then forced down so that its pin 22engages with the inner inclined faces of the blades Y14. and forces theblades outwardly below and beyond the sides of the lower end of the tubeor casing 10. When the bit is rotated the blades 14: cut the wall of thewell to a diameter slightlv greater than the diameter of the tube 10,thus enabling the operator to use an additional tube section of the samediameter as the first one.

When lowering the drill bit into the tube 10, the smaller tube 20 iselevated so that the pin 22 is out of contact with the blades, thuspermitting the blades to lie within the casing 11, and the casing toslide easily downwardly into the tube 10. When the .bit has passed belowthe lower end of the tube 10, the tube 20 is pressed down to spread theblades, after which the bit is rotated to cut the well.

What is claimed is:

1. An underreaming well drill including a casing having a drill bitsecured in one end and a tube secured in the other end, the tube havinga longitudinal slot on each side, a rod slidable in the tube and havinga head formed with a central longitudinal pin for projection into thecasing, the sides of the casing being formed with longitudinal slots,and cutting blades pivotally mounted in the casing slots and havinginner inclined faces positioned for engagement by the pin to be swungoutwardly through the slots into cutting position, and means engagedthrough the rod and projecting into the slots of the tube for limitingthe movement of the rod.

2. An underreaming well drill. including a casing having a drill bitsecured in one end and a-tube secured in the other end, a rod slidablein the tube and having a head formed with a central longitudinal pinprojecting into the casing, cutting blades pivotally mounted in thecasing and having inner inclined faces positioned for engagement by thepin to be swung outwardly into cutting position, and means engagedthrough the rod and the tube for limiting the movement of the rod.

3. An underreaming Well drill including a casing having a drill bit inone end and a tube in the othertend, a rod slidable in the tube andprojectable into the casing, cutting blades pivotally supported in thecasing and projectablethrough the sides of the casing by thesaid rod,and means carried by the rod and slidably engaged with the tube forlimiting the longitudinal movements of the rod in the tube andv theconsequent projection of the cutting blades.

In testimony whereof I aflix my signature, in the presence of twowitnesses.

LOUI H. BALDWIN.

Witnesses: I y

W. R. W THINeroN, HAROLD L.

